This invention relates to a novel apparatus and method for establishing an annulus access connection with a wellhead housing using the weight of the valve connection apparatus to aid in positioning and securing the valve connection apparatus and thereby eliminate the need for remotely operable robotic manipulators in performing such operations.
Horizontal annulus connections are typically made using an active method, i.e., requiring a combination of remotely operable robotics and remotely operated vehicle. In using this method four distinct operational stages are required to make a horizontal connection. The first stage requires a valve and connector assembly to be landed in close proximity of the remotely operable robotics. The second stage requires engaging the remotely operable robotics with the valve and connector assembly. The third stage requires operating the remotely operable robotics to preload the mating hubs of the connector and the annulus access port. The fourth stage calls for the connector to be closed to establish a fluid tight connection between the valve and connector assembly and the annulus access port. This four stage sequence requires the remotely operable robotics to perform a series of complex operations to provide for the initial alignment and preloading of the annulus connection.
The use of these remotely operable robotics requires great skill and dexterity by the operator to be properly performed. The robotics themselves are complex hydraulically operated mechanical apparatus which are expensive to operate and require considerable maintenance. The present invention overcomes these problems by providing a novel method and apparatus for installing a valve and connector assembly without requiring the use of such complex and expensive extraneous machines.
U.S. Pat. No. 3,592,014 to W. Brown et al. discloses a system for remotely making flowline connections in a subsea environment which utilizes a stinger connector and float positioned on one of the flowline ends. The stinger connector and float are pulled down to a subsea station where the stinger connection is made.
U.S. Pat. No. 4,676,696 to N. K. Laursen is an example of another apparatus used to install a flowline section in a horizontal position at the seabed. A vertically disposed guide tube with guide funnel is positioned on a subsea manifold and receives a mandrel on the end of the flowline which is lowered vertically. The mandrel is shaped to cooperate with the guide tube and can be pivoted into a horizontal position after the connection is made.
U.S. Pat. No. 4,784,525 to D. Francois discloses an apparatus for installing equipment subsea in a horizontal position. A servicing module is lowered to a submerged unit and connected thereto by a hydraulically actuated bolt screwing mechanism.
U.S. Pat. No. Re. 27,340 to L. E. Williams et al. discloses an apparatus for connecting a subsea tree to a horizontally disposed flowline axially spaced therefrom. A connector body is lowered from the surface into position between the adjacent ends and operated to establish a fluid tight connection between the two members.